California’s Electric Blue Waves

The sun sets off the coast of San Clemente, California

After weeks of staying within about a five-mile radius of home, this past weekend we headed down Interstate 5 to San Clemente in south Orange County, California. The main purpose was to celebrate Mother’s Day with the Grammy and Grandpa Haas, who we haven’t seen since the beginning of the stay at home orders. The side benefit was that we got a close up view of the phenomena lighting up the Southern California coast with phosphorescent blue.

Red tide is a collective term for algal blooms that occur in saline environments. According to the National Oceanic and Atmospheric Administration (NOAA), almost every coastal state in the U.S. has experienced some type of algal overgrowth. Not all of these blooms are harmful, nor are they always red, which makes ‘red tide’ a bit of a misnomer. The red tides off the coast of Southern California are caused by photosynthetic phytoplankton called dinoflagellates, whose pigments used to collect sunlight for photosynthesis have a reddish or brown color. These color the ocean waters a murky red or brown color. Indeed, we noticed the unusually brown sea foam on the beach on our morning walk. There are some red tides caused by species that produce toxins that are harmful to ocean animals, and some can even be harmful to humans. The good news is that the algal blooms off the California coast are usually not caused by toxic dinoflagellates, although sensitive individuals can experience irritation when coming into contact with them. And while kinda ugly during the day, these microscopic organisms put on an electric light show after dark.

The choppy waters were more brown than usual.

The first time I ever observed oceanic bioluminescence was in about the same location, nearly 20 years ago. It was a summer evening, the night of my eighteenth birthday. I was camping with some friends at the San Mateo Campground, just south of San Clemente State Beach. I was mesmerized by the neon blue light streaking across the foam as the waves broke along the shore. Almost 20 years later, I was able to share the experience with my own kids as we watched the dazzling blue waves crash along the Southern California shore just outside their grandparents’ home.

The nighttime photos, taken on Emily’s iPhone 11, do not do justice to how truly spectacular this bioluminescent event really was. Even with the best of cameras, this is something that is best watched up close. We were glad to be able to view this phenomenon before it headed out to sea.

Please note that at time of writing, many of California’s state beaches are still closed due to the COVID19 safer-at-home measures. That said, some cities are opening up their beaches to people for surfing and other forms of exercise, as long as physical distancing measures are adhered to. Please check local guidance before heading out. Also in other good news, parks and trailheads are beginning to open up again. So get outdoors, bring a mask and enjoy some happy trails. I hope to see you outside- six feet apart of course!